A common conventional coffee maker shown in FIG. 1 includes a body 1 provided with a water storing space 14, and a heater 10 provided under the water storing space 14.
The heater 10 consists of a metal plate 11 and an electrical heating tube 12 wrapped in the metal plate 11. Then the heating tube 12 is powered to generate heat, which is then transmitted to the metal plate to boil up the water in the water storing space 14 in the body 1 for making coffee.
However, the conventional coffee maker has the following disadvantages.
1. As the metal plate directly wraps up the electrically heating tube 12, it has to be provided with extremely good insulating effect, otherwise it would be dangerous to use this conventional coffee maker.
The heat generated by the electrically heating tube 12 has to be transmitted to the metal plate, and then to the water in the water storing space 14, having inferior heat transmission by means of the small dimension contact between the heating tube 12 with the metal plate 11.